Metabolomic and genomic insights into TMA degradation by a novel halotolerant strain - Paracoccus sp. PS1

Trimethylamine N-oxide (TMAO) is a gut metabolite that acts as a biomarker for chronic diseases, and is generated by the oxidation of trimethylamine (TMA) produced by gut microflora. Since, microbial degradation of TMA is predicted to be used to restrict the production of TMAO, we aimed to isolate bacterial strains that could effectively degrade TMA before being oxidized to TMAO. As marine fish is considered to have a rich content of TMAO, we have isolated TMA degrading isolates from fish skin. Out of the fourteen isolates, depending on their rapid TMA utilization capability in mineral salt medium supplemented with TMA as a sole carbon and nitrogen source, isolate PS1 was selected as our desired isolate. Its TMA degrading capacity was further confirmed through spectrophotometric, Electrospray Ionization Time-of-Flight Mass Spectrometry (ESI TOF-MS) and High performance liquid chromatography (HPLC) analysis and in silico analysis of whole genome (WG) gave further insights of protein into its TMA degradation pathways. PS1 was taxonomically identified as Paracoccus sp. based on its 16S rRNA and whole genome sequence analysis. As PS1 possesses the enzymes required for degradation of TMA, clinical use of this isolate has the potential to reduce TMAO generation in the human gut.

Biocontrol of biofilm forming Burkholderia cepacia using a quorum quenching crude lactonase enzyme extract from a marine Chromohalobacter sp. strain D23

Biofilm plays advantageous role in Burkholderia cepacia by exerting multi-drug resistance. As quorum sensing (QS) system regulates biofilm formation and pathogenicity in B. cepacia strains, quorum quenching (QQ) may be a novel strategy to control persistent B. cepacia infections. In these regards, 120 halophilic bacteria were isolated from marine sample and tested using Chromobacterium violaceum and C. violaceum CV026-based bioassays initially, showing reduced violacein synthesis by QQ enzyme by 6 isolates. Among them, Chromohalobacter sp. D23 significantly degraded both C6-homoserine lactone (C6-HSL) and C8-HSL due to potent lactonase activity, which was detected by C. violaceum CV026 biosensor. Further high-performance liquid chromatography (HPLC) study confirmed degradation of N-acyl homoserine lactones (N-AHLs) particularly C6-HSL and C8-HSL by crude lactonase enzyme. Chromohalobacter sp. D23 reduced biofilm formation in terms of decreased total biomass and viability in biofilm-embedded cells in B. cepacia significantly which was also evidenced by fluorescence microscopic images. An increase in antibiotic susceptibility of B. cepacia biofilm was achieved when crude lactonase enzyme of Chromohalobacter sp. strain D23 was combined with chloramphenicol (1-5 × MIC). Chromohalobacter sp. D23 also showed prominent decrease in QS-mediated synthesis of virulence factors such as extracellular polymeric substances (EPS), extracellular protease, and hemolysin in B. cepacia. Again crude lactonase enzyme of Chromohalobacter sp. strain D23 inhibited B. cepacia biofilm formation inside nasal oxygen catheters in vitro. Finally, antibiotic susceptibility test and virulence tests revealed sensitivity of Chromohalobacter sp. strain D23 against a wide range of conventional antibiotics as well as absence of gelatinolytic, hemolytic, and serum coagulating activities. Therefore, the current study shows potential quorum quenching as well as anti-biofilm activity of Chromohalobacter sp. D23 against B. cepacia.

Unveiling of a smartphone-mediated ratiometric chemosensor towards the nanomolar level detection of lethal CN-: combined experimental and theoretical validation with the proposition of a molecular logic circuitry

A promising naphthalene-functionalized ratiometric chemosensor (E)-1-((naphthalen-5-yl) methylene)-2-(2,4-dinitrophenyl) hydrazine (DNMH) is unveiled in the present work. DNMH demonstrates brisk discernible colorimetric response from yellow to red in the presence of CN⁻, a lethal environmental contaminant, in a near-perfect aqueous medium with a LOD of 278 nM. The “key role marker” controlling the electrochemical and non-covalent H-bonding interaction between DNMH and CN⁻ is through the commendable role of acidic –NH functionalities. Kinetic studies reveal a pseudo second order reaction rate and the formation of an unprecedented photostable adduct. The negative value of ΔG as evaluated from ITC substantiates the spontaneity of the DNMH⋯CN⁻ interaction. The sensing mechanism was further reinforced with state-of-the-art theoretical investigations, namely DFT, TDDFT and Fukui indices (FIs). Moreover, the proposition of a reversible multi-component logic circuitry implementing Boolean functions in molecular electronics has also been triggered by the turn-over spectrophotometric response of the ditopic ions CN⁻ and Cd²⁺. The cytotoxicity of DNMH towards Bacillus thuringiensis and Escherichia coli is successfully investigated via the MTT assay. Impressively, “dip stick” and “easy to prepare” test paper device and silica gel-based solid-phase CN⁻ recognition validate the on-site analytical application of DNMH. Furthermore, the involvement of a synergistic approach between ‘chemistry beyond the molecule’ and ‘engineering’ via an exquisitely implemented smartphone-assisted colorimetric sensory prototype makes this work unprecedented among its congeners and introduces a new frontier in multitudinous material-based functional product development.

A ratiometric chemosensor (DNMH) is unveiled herein, demonstrating selective chromogenic response towards CN⁻, with a LOD of 278 nM. Consequently, molecular logic circuitry and a smartphone-based colorimetric sensory prototype has been explored.

Leptin and obesity

An imbalance between calorie intake and energy expenditure produces obesity. It has been a major problem in societies of the developing and developed world. In obesity an excessive amount of fat accumulates in adipose tissue cells as well as in other vital organs like liver, muscles, and pancreas. The adipocytes contain ob genes and express leptin, a 16 kDa protein. In the present communication, we reviewed the molecular basis of the etiopathophysiology of leptin in obesity. Special emphasis has been given to the use of leptin as a drug target for obesity treatment, the role of diet in the modulation of leptin secretion, and reduction of obesity at diminished level of blood leptin induced by physical exercise.

Effect Of Transtibial Prosthesis Mass On Gait Asymmetries

BACKGROUND

Individuals with transtibial amputation (TTA) typically walk with an asymmetrical gait pattern, which may predispose them to secondary complications and increase risk of fall. Gait asymmetry may be influenced by prosthesis mass.

OBJECTIVES

To explore the effects of prosthesis mass on temporal and limb loading asymmetry in people with TTA following seven days of acclimation and community use.

METHODOLOGY

Eight individuals with transtibial amputation participated. A counterbalanced repeated measures study, involving three sessions (each one week apart) was conducted, during which three load conditions were examined: no load, light load and heavy load. The light load and heavy load conditions were achieved by adding 30% and 50% of the mass difference between legs, at a proximal location on the prosthesis. Kinematic and ground reaction force data was captured while walking one week after the added mass. Symmetry indices between the prosthetic and intact side were computed for temporal (Stance and Swing time) and limb loading measures (vertical ground reaction force Peak and Impulse).

FINDINGS

Following seven days of acclimation, no significant differences were observed between the three mass conditions (no load, light load and heavy load) for temporal (Stance time: p=0.61; Swing time: p=0.13) and limb loading asymmetry (vertical ground reaction force Peak: p=0.95; vertical ground reaction force Impulse: p=0.55).

CONCLUSIONS

Prosthesis mass increase at a proximal location did not increase temporal and limb loading asymmetry during walking in individuals with TTA. Hence, mass increase subsequent to replacing proximally located prosthesis components may not increase gait asymmetry, thereby allowing more flexibility to the clinician for component selection.

Occurrence, management and outcome of immune-complex glomerulonephritis in dogs with suspected glomerulopathy in the UK

OBJECTIVES

To determine the proportion of dogs diagnosed with immune-complex glomerulonephritis in a large cohort of UK dogs with clinical suspicion of glomerular disease in which renal histopathology, including routine light microscopy, transmission electron microscopy and immunofluorescence, had been performed. The second objective was to describe treatment and long-term clinical outcome of dogs diagnosed with immune-complex glomerulonephritis.

MATERIALS AND METHODS

Sixty-two UK dogs that underwent renal biopsies for investigation of suspected glomerulopathy (urine protein-to-creatinine ratio persistently >0.5) were included in this retrospective multicentre study. Signalment, clinico-pathological abnormalities, histopathological diagnosis, treatment following diagnosis and survival were recorded.

RESULTS

Seventeen (27%) of the dogs with suspected glomerular disease were diagnosed with immune-complex glomerulonephritis and nine (53%) of these were still alive at the study end point, with a median follow-up of 366 days (range 52 to 1299). Six dogs diagnosed with immune-complex glomerulonephritis were treated with mycophenolate. Four received mycophenolate alone for immunosuppression and two received mycophenolate and chlorambucil; all these six dogs were alive at data collection [median follow-up time 712.5 days (range 73 to 1299)]. Seven dogs diagnosed with immune-complex glomerulonephritis did not receive immunosuppressive treatment; only one of these dogs was alive at study end point [median survival time 302 days (range 52 to 723)].

CLINICAL SIGNIFICANCE

Immune-complex glomerulonephritis may be less common in the UK than previously reported in North America and mainland Europe, reducing the likelihood of treatment modification following renal biopsy. Mycophenolate was the most commonly used immunosuppressant for cases of immune-complex glomerulonephritis.

Association between ultrasonographic appearance of urine and urinalysis in dogs and cats

OBJECTIVE

To evaluate association between ultrasonographic urine echogenicity and sediment examination in dogs and cats.

MATERIALS AND METHODS

Dogs and cats undergoing ultrasound-guided cystocentesis at a multidisciplinary referral hospital. Ultrasonographic images were stored and reviewed by a single, blinded, board-certified radiologist. Urine appearance was described as "echoic" or "anechoic". Urine sediment was examined for bacteriuria, pyuria, haematuria, crystalluria and urine-specific gravity and then classified as "active" or "inactive."

RESULTS

Of the 194 cases included in this study, urine was echoic in 52 and anechoic in 142. Sediment was active in 52 and inactive in 142 samples. Sensitivity and specificity of echoic urine for active sediment were 40% (95% CI: 27 to 55%) and 78% (95% CI: 70 to 85%), respectively. Positive predictive value and negative predictive value of echoic urine for active sediment were 40% (CI 30 to 52%) and 78% (CI 74 to 82%), respectively. If urine-specific gravity was <1.015 urine was always described ultrasonographically as anechoic.

CLINICAL SIGNIFICANCE

Association between sediment analysis and ultrasonographic appearance of urine is poor. Echoic urine had low positive predictive value for active sediment in this study, suggesting that echoic urine alone should not prompt urinary investigations in the absence of other clinical suspicion. Despite a negative predictive value of 78%, urinalysis is still indicated for anechoic urine, especially if urine specific gravity is low.

Clinical leishmaniasis in dogs living in the UK

OBJECTIVES

To investigate the prevalence of leishmaniasis in dogs in the UK and to describe clinical presentation, clinicopathological abnormalities, therapeutic protocols and outcome in this non-endemic country.

MATERIALS AND METHODS

Medical records of dogs diagnosed with leishmaniasis at seven referral centres in the UK were retrospectively reviewed.

RESULTS

The prevalence was between 0·007 and 0·04% with a higher number of cases in southern England. All dogs had a history of travel to or from an endemic country. Lethargy, dermatological disease, decreased appetite and lameness were the most common reasons for presentation. Allopurinol was used alone for treatment in the majority of cases.

CLINICAL SIGNIFICANCE

Although rare, leishmaniasis should be considered in dogs in the UK if they have compatible clinical signs and history of travel to or from endemic areas.

Unusual Grignard Reaction of α-Arylcinnamonitriles [1]

Reaction of α-arylcinnamonitriles with excess of alkylmagnesium halide yielded predominantly the erythro isomer of α,β-dialkyl-α,β-diarylpropionitriles. PMR spectra of the diastereoisomers have been described.

White blood cell count and the sodium to potassium ratio to screen for hypoadrenocorticism in dogs

BACKGROUND

Abnormal sodium to potassium (Na:K) ratios can raise suspicion for hypoadrenocorticism (HA). Although dogs with HA usually have normal leukograms, their white blood cell counts may be useful in screening for HA.

OBJECTIVES

To examine the utility of combining the Na:K ratio with white blood cell counts to screen for HA in hospitalized dogs requiring fluid treatment administered i.v..

ANIMALS

Fifty-three dogs with confirmed HA and 110 sick dogs confirmed not to have HA.

METHODS

Retrospective, case-control study. Dogs were included if they were hospitalized and administered fluids i.v., had a complete blood count and measurement of serum Na and K concentrations. HA was diagnosed using an ACTH stimulation test, or ruled out by measurement of basal serum cortisol concentration.

RESULTS

The receiver operating characteristic (ROC) curve for the lymphocyte count was not significantly different from the ROC curve of the Na:K ratio (P = .55). The ROC curve for the model combining the Na:K ratio and lymphocyte count was superior for identifying dogs with HA compared to the Na:K ratio (P = .02) or lymphocyte count (P = .005) alone. At the 100% sensitivity cutoff, lymphocyte count was more specific for detection of HA than Na:K (P < .001).

CONCLUSIONS AND CLINICAL IMPORTANCE

A combination of the Na:K ratio and lymphocyte count provides a better screening test for HA compared to the Na:K ratio or lymphocyte count alone. At 100% sensitivity, the lymphocyte count is a more specific test for HA than the Na:K.

Sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) gene silencing and remodeling of the Ca2+ signaling mechanism in cardiac myocytes

Transient elevations of cytosolic Ca2+ are a common mechanism of cellular signaling. In striated muscle, the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) plays an important role in terminating Ca2+ transients by returning cytosolic Ca2+ to intracellular stores. Stored Ca2+ can then be released again for subsequent signaling. We down-regulated SERCA2 gene expression in cultured cardiac myocytes by means of endogenous transcription of small interfering RNA encoded by an exogenous cDNA template. The cDNA template was delivered by adenovirus vector. Reduction of SERCA expression in all myocytes in culture was documented by immunochemistry, real-time RT-PCR, and determination of ATP-dependent Ca2+ transport. The reduction of SERCA2 expression was associated with the up-regulation of transient receptor potential (TRP) channel proteins (TRPC4 and TRPC5) and Na+/Ca2+ exchanger, indicating that intracellular store deficiency was compensated for by Ca2+ fluxes through the plasma membrane. In fact, SERCA silencing was followed by increased transcription of Na+/Ca2+ exchanger, TRPC4, TRPC5, and related transcriptional factors, such as stimulating protein 1, myocyte enhancer factor 2, and nuclear factor of activated cells 4, through activation of calcineurin. This finding demonstrates that the observed compensation occurs through transcriptional crosstalk and the remodeling of Ca2+ signaling pathways. The wide significance of this regulatory mechanism is related to its general involvement in Ca2+ signaling dynamics and in cardiac development and hypertrophy.

MRI of spinal intradural arachnoid cyst formation following tuberculous meningitis

Secondary intradural arachnoid cyst involving the spine is uncommon. It is usually secondary to trauma, haemorrhage, surgery or inflammation. We present two cases of treated tuberculous meningitis, which presented with gradual onset of quadriplegia and paraplegia, respectively. MRI revealed intradural (cervical and thoracic) arachnoid cysts (ventral and dorsal to the spinal cord) with myelomalacic cord changes. Ventral location of such spinal arachnoid cysts, and being secondary to tuberculous arachnoiditis are distinctively uncommon features. The rarity of this condition and the relevance of MRI in the accurate diagnosis have been discussed here.

Dependence of relativistic effects on electronic configuration in the neutral atoms of d- and f-block elements

Although most neutral d- and f-block atoms have nd(g-2)(n + 1)s(2) and (n - 1)f(g-2)(n + 1)s(2) ground configurations, respectively, where g is the group number (i.e., number of valence electrons), one-third of these 63 atoms prefer a higher d-population, namely via (n + 1)s-->nd "outer" to "inner" electron shift (particularly atoms from the second d-row), or via (n - 1)f-->nd "inner" to "outer" electron shift (particularly atoms from the second f-row). Although the response to the modified self-consistent field is orbital destabilization and expansion for (n + 1)s-->nd, and stabilization and contraction for (n - 1)f-->nd, the relativistic modification of the valence orbital responses is stabilization in both cases. This is explained by double perturbation theory. Accordingly, electron configuration and relativity trigger the orbital energies, the orbital populations and the chemical shell effects in different ways. The particularly pronounced relativistic effects in groups 10 and 11, the so-called gold maximum, occur because of particularly efficient cooperative nonrelativistic shell effects and relativistic stabilization effects (inverse indirect effect) at the end of the d-block.

Syntheses and anthelmintic activity of alkyl 5(6)-(substituted carbamoyl)- and 5(6)-(disubstituted carbamoyl)benzimidazole-2-carbamates and related compounds

A number of alkyl 5(6)-(substituted-carbamoyl)- and 5(6)-(disubstituted-carbamoyl)benzimidazole-2-carbamates and related compounds have been synthesized, and their anthelmintic activity against various intestinal helminths of experimental animals have been evaluated. A large percentage of the compounds synthesized showed noteworthy activity against Ancylostoma ceylanicum and at higher doses against Hymenolepsis nana infections. Compared to the alkyl 5(6)-(substituted-carbamoyl)benzimidazole-2-carbamates, the disubstituted carbamoyl analogues were found to exhibit better anthelmintic activity. The most active compound of the series, namely, methyl 5(6)-[(N-2-pyridylpiperazino)carbamoyl]benzimidazole-2-carbamate (90), has been screened against intestinal helminths in higher animals and as a micro- and macrofilaricidal agent. Compound 90 has been identified as a broad-spectrum anthelmintic agent. Compound 90 has been identified as a broad-spectrum anthelmintic in view of its efficacy against A. ceylanicum (hamsters and dogs), H. nana (rats), Nippostrongylus brasiliensis (rats), Syphacia obvelata (mice), A. tubaeformis (cat), Toxocara spp. (cat), and Litomosoides carinii (cotton rat).

Dimers of Podocarpic Acid Derivatives

Treatment of methyl 12-hydroxypodocarpa-8,11,13-trien-19-oate (5) with a commercial sample of thallium(III) trifluoroacetate gave a low yield (5%) of a non-symmetric ether-linked dimer (15). Use of freshly prepared thallium(III) trifluoroacetate gave a 28% yield of the symmetrical biaryl dimer (16). The dimethyl ether (17) was prepared in low yield (10%) by treatment of methyl 12-methoxypodocarpa-8,11,13-trien-19-oate (4) with the latter reagent.

Multi-input optical parallel logic processing with the shadow-casting technique

The lensless shadow-casting technique for coded pattern processing usually accommodates two inputs at a time to perform desired logical operations in parallel. A method of binary encoding is proposed that can accommodate multiple input patterns for simultaneous processing. With the proposed multiple-input encoding a carry-look-ahead technique of binary addition is developed that requires fewer processing steps than the conventional ripple-carry method. Experimental results for a few logic-processing operations are included to establish the validity of the proposed technique.

Topical atropine and timolol therapy in failed retinal detachment surgery

We conducted a double-blind randomized prospective study to evaluate the efficacy of topical timolol alone and topical timolol and atropine combined in cases of operated failed retinal detachment surgery cases in which no apparent open break explained the surgical failure. In both groups with and without proliferative vitreoretinopathy no statistically significant difference in retinal reattachment was found.

Reversal of chloroquine resistance in Plasmodium falciparum by CDR 87/209 and analogues

The spreading of resistance towards chloroquine has diminished its value as a potent and safe drug in malaria endemic areas. Recent reports on the reversal of chloroquine resistance in the malaria parasite Plasmodium falciparum in vitro and in vivo by verapamil, desipramine and other Ca(2+)-channel blockers and antidepressants has initiated a strategy for chemotherapy by treatment with chloroquine in combination with a drug resistance modulator. Described here is a class of modulators of distinct structure which reverse chloroquine resistance in a different manner. Contrary to verapamil and desipramine, CDRI 87/209, the most potent compound of this new class and used as a chemical lead, did not restore chloroquine accumulation in the resistant parasites, thereby indicating that besides the proposed blockade of drug efflux other mechanisms are vulnerable targets for a chemotherapeutic approach towards drug resistance. Similar to the former modulators, CDRI 87/209 showed only weak intrinsic plasmodicidal activity and the increase of drug susceptibility was restricted to resistant plasmodia.

Effect of five-membered heterocycles against Leishmania donovani infection

Impact of change of heteroatom in pentavalent heterocycles, viz., pyrroles, isoxazoles, imidazoles and crotonates on the profile of antileishmanial activity against amastigotes of L. donovani using in vivo test system and macrophage-amastigote culture system has been studied. Sixty-three compounds were tested. Nine imidazoles showed marginal activity in vivo, whereas 3 out of 10 compounds of isoxazolone series and 2 out of 4 substituted aminocrotonates exhibited antileishmanial activity. Of the 30 substituted pyrroles, except 8 all showed antileishmanial activity in vivo on day 7 post treatment.

Pregnancy interceptive efficacy and biological profile of 3-amino-6,7-dimethoxy-1H-pyrazolo [3,4-b] quinoline (compound 85/83) in rodents

Administration of compound 85/83 during the peri- and post-implantation period intercepted pregnancy in hamster and guinea pig by parenteral route and in hamster by oral route also. The m.e.d. for hamster and guinea pig was 10 and 20 mg/kg, respectively; lower doses were less effective. Restricting the administration to early post-implantation schedule interrupted pregnancy partially in both species. The compound was, however, ineffective in rat and in the pre-implantation schedule (days 1-4 post-coitum) in hamster. When tested in vitro on growing trophoblasts at 13.8 x 10(-5) M concentration, it prevented growth and caused degeneration of the cells within 24 h; lower concentration (9.2 x 10(-5) M) was less effective. The compound was found to be devoid of estrogenic, antiestrogenic, progestational and antiprogestational properties in conventional bioassays. In hormone competition assays, its relative binding affinity (RBA) to estrogen receptor was negligible (0.002% of estradiol-17 beta), while for uterine cytosol progesterone receptors in rabbit and hamster was 0.06 and 0.08% of progesterone, respectively. The compound 85/83 appears to intercept pregnancy by interfering with development of trophoblast cells.

Regioselective reactions of 1,2-dehydroprogesterone: syntheses of pregnane derivatives as possible contragestational agents

A few pregnane derivatives were synthesized from 1,2-dehydroprogesterone (1). Ring A of 1,2-dehydroprogesterone was aromatized without affecting C-20, and the resulting acetoxy compound (2) after hydrolysis yielded 1-hydroxy-4-methyl-19-norpregna-1,3,5(10)-trien-20-one (3). Reactions of the phenol (3) with alkyl halides yielded the ethers 6a-6b and 7. Opening of the oxirane ring in 7 with secondary amines furnished the aminoalcohols 8a-8b. Friedelcraft's reaction of 3 with maleic anhydride and chloracetyl chloride led to the formation of 9 and 10, respectively. Base-catalyzed ring closure of 10 yielded 1-acetyl-12a-methyl-8-oxo-5[H]-1,2,3,3a,3b,4,8,9,10b,11,12, 12a-dodecahydrocyclopenta (7,8)-phenanthro (3,4-b) furan (11), which reacted with aromatic aldehydes regioselectively to furnish 12a-12b. Reaction of 1 with triethylorthoformate in the presence of boron trifluoride etherate involved the participation of C-21, and the carbonyl at C-3 remained unaffected. The product 13 was identified as 21-[2-hydroxyvinyl]-21-norpregna-1,4-diene-3,20-dione. Reductive amination with sodium cyanoborohydride in the presence of ammonium acetate did not attack ring A and smoothly furnished the amine 14 which, on reaction with succinic anhydride, gave 20-succinamylpregna-1,4-dien-3-one (15).

Chemotherapy of filariasis--on the search of new agents effective on the reproductive system of female adult worms

The design and synthesis of a series of alkyl 5(6)-substituted benzimidazole-2-carbamates (1-13), 7-chloro-4-(4-substituted phenyl)aminoquinolines (14-16), 1,2-dimethyl-3-methoxy-carbonyl-4,5-disubstituted pyrroles (17-19) and some compounds belonging to the class pimelonitrile (20), dihydroquinoline (21), pyridine (22), pyridoquinoline (23) and tetrahydro-pyrimidine (24) have been carried out as possible antifilarial agents. All these compounds have been evaluated for their activity against male and female adult worms of Litomosoides carinii in cotton rats. The effect of these compounds was also observed on the reproductive system (condition of developing microfilariae and their release from uterus) of adult female worms. In this study, three types of compounds were discovered: (a) those which showed activity on both the male and female adult worms and also had sterilizing effects on surviving adult females (1-3, 6-9, 13, 19), (b) those which only sterilized the adult females (14-16, 21, 24), and (c) those which had no effect on female reproduction but killed only adult worms (4, 5, 11, 12, 17, 18, 20, 22, 23). This tends to open up a new avenue in the chemotherapy of filariasis and the future scope of work on chemosterilization of adult females has been discussed.

Radical curative activity of a new 8-aminoquinoline derivative (CDRI 80/53) against Plasmodium cynomolgi B in monkeys

An analogue of primaquine, N1-(3-acetyl-4-5-dihydro-2-furanyl)-N4-(6-methoxy-8-quinolinyl) 1,4-pentanediamine, CDRI Code 80/53), has been evaluated for anti-relapse activity against sporozoite induced Plasmodium cynomolgi B infection in rhesus monkeys. The compound has shown 100% curative anti-relapse activity at 1.25 mg/kg x 7 day dose schedule, thereby giving a primaquine index of 0.8. The compound is currently under Phase-I clinical trials.

Exploration of antileishmanial activity in heterocycles; results of their in vivo & in vitro bioevaluations

A total of 51 imidazoles, pyrroles, quinolines and isoxazolines compounds were screened for antileishmanial activity in vivo and in vitro, using Leishmania donovani as the test parasite. The screening revealed hitherto unknown antileishmanial activity in these heterocycles. Three of the compounds screened (one belonging to isoxazoline series and two from pyrrole series) showed significant anti-leishmanial activity, ranging from 86-91 per cent inhibition in hamsters. When tested in vitro, using macrophage amastigote culture system, these compounds showed inhibition of 62-78 per cent at 30 micrograms/ml concentration.

Syntheses and bioevaluation of substituted dihydropyridines for pregnancy-interceptive activity in hamsters

A number of 2,6-dimethyl-3,5-bis(methoxycarbonyl)-4-substituted-1,4- dihydropyridines were synthesized and evaluated for pregnancy-interceptive activity in mated hamsters. Out of 24 compounds, 12, 15, 21, 22, 28, and 34 caused a marked reduction in the number of implantations when administered on days 3-8 postcoitum. In an in vitro competition assay, none of the compounds exhibited noticeable binding affinity for uterine progesterone receptors. The results reported here have helped to identify new leads for developing pregnancy-interceptive agents and the active compounds do not seem to elicit their interceptive effect through receptor-mediated inhibition of progesterone action in hamster uterus.

Temporal fluctuations in HIV quasispecies in vivo are not reflected by sequential HIV isolations

A genetic study has been made of the HIV tat gene from sequential HIV-1 isolates and the corresponding infected peripheral blood mononuclear cells. DNA was amplified by polymerase chain reaction (PCR) and cloned into a eukaryotic expression vector. Twenty clones were sequenced from each sample. Comparing the sequential HIV isolates, abrupt differences were seen between the major forms of each isolate. These progressive changes were not reflected at all among the in vitro samples. The fluctuation in the quasispecies in vivo may suggest a much more dynamic role for latently infected mononuclear cells. High frequencies of functionally defective tat genes were identified. Given such complexity and the evident differences between quasispecies in vivo and in vitro, the task of defining HIV infection in molecular terms will be difficult.

Molecular interaction of non-steroidal compounds with uterine progesterone receptor (Part II)

Some possible non-steroidal antiprogestins were evaluated for their receptor binding activity by competitive protein binding assay in rabbit as well as human uterine cytosol in vitro. Of the 42 compounds belonging to 5 different series tested, dimethyl ester of monobenzylidene succinic acid, 4-ethoxycarbonyl-3-(m-methoxybenzyl)-5-(m-anisyl)-gamma-butyrolact one and 2-(3-benzyl-oxybenzyl)-3-(3-acetoxybenzyl)butane-1,4-diol exhibit around 20% inhibition of 3H-progesterone binding to uterine cytosol in both species.

Contraceptive and hormonal properties of a new 1,4-dihydro-2-oxoquinoline derivative (compound 84-182) in rodents and rhesus monkeys

Compound 84-182 prevented pregnancy when administered subcutaneously at 10 mg/kg dose on days 3-8 post-coitum in hamsters and on days 6-10 post-coitum in guinea pigs. At lower doses, while in hamsters there was a marked reduction in implantation number, majority of implantations in guinea pigs showed signs of resorption. The compound was ineffective when administered at 10 mg/kg dose on days 1-3 or 6-7 post-coitum in hamsters and on days 1-5 or 4-8 post-coitum in rats. In rhesus monkeys, treatment with the compound at 5 and 10 mg/kg doses on days 16-21 of the menstrual cycle induced frank vaginal bleeding between days 21 and 24. Treatment on days 21-30 or after confirmation of pregnancy on days 32-36 was ineffective. In conventional bioassays, the compound was devoid of any estrogenic, antiestrogenic, progestational, antiprogestational, androgenic or antiandrogenic properties at the contraceptive dose. In competitive protein binding assay, the compound showed relative binding affinity (RBA) of less than 0.1% and 0.28% of progesterone, respectively, for rabbit and hamster uterine cytosol progesterone receptors. Its RBA for rat uterine cytosol estrogen receptors was less than 0.1% of estradiol-17 beta.

Molecular interaction of nonsteroidal compounds with uterine progesterone receptor (Part I)

Progesterone-receptor binding affinity of some nonsteroidal molecules was assessed by competitive protein binding assay in rabbit as well as human uterine cytosol in vitro. Of 40 compounds belonging to 5 different series tested, 3-(p-anisoyl)-2-chloro-6, 7-dimethoxy-quinoline exhibited around 50% inhibition whereas 2-(p-anisoyl) naphthalene and 3-substituted phenyl-1-(3-(2-chloro-6, 7-dialkoxy) quinolinyl)prop-2-en-1-one showed around 20% inhibition in 3H-progesterone binding for rabbit and human uterine progesterone receptor.

Specific interaction of some non-steroidal compounds with the progesterone binding site of uteroglobin

Uteroglobin binds progesterone with high affinity. A few substituted diphenyl ketones were observed to inhibit uteroglobin-progesterone binding in a dose-dependent manner. 4,4'-Dimethoxy-2-hydroxy benzophenone had relatively higher affinity for uteroglobin. The structure-activity relationship amongst the substituted diphenyl ketones indicated considerable sensitivity towards minor structural modifications. These observations offer a tool to investigate nonsteroidal compounds in relation to progesterone related functions of uteroglobin in pregnancy.

Fertility impairment in females--present status

Various approaches towards the control of fertility in females have been discussed. The salient observations made in the field of reproductive physiology which may generate new leads for the development of agents capable of inhibiting pregnancy, are described. The discussion concerning the oestrogen and progesterone receptors is directed towards designing new antifertility agents. The different areas of fertility control covered in this survey are of importance for basic and applied research.